Mating occurs in the water. Nests are dug in well-drained, sunny areas such as grass tussocks, hammocks of sphagnum moss, and marshy pastures. Forages in the water. Burrows into mud or under vegetation to sleep or else sleeps in the burrow of another animal. In some parts of its range, spends considerable time on land (Ernst et al. 1994).

NATURE SERVE GLOBAL HABITAT COMMENTS:

Mostly unpolluted, small, shallow bodies of water such as small marshes, marshy pastures, bogs, fens, woodland streams, swamps, small ponds, and vernal pools; also occurs in brackish tidal streams. Ponds surrounded by relatively undisturbed meadow or undergrowth are most favorable. Favors waters with soft bottom and aquatic vegetation. Often basks along water's edge, on brush piles in water, and on logs or vegetation clumps. May spend much time on land in some areas during certain seasons. When inactive, hides in bottom mud and detritus, or in muskrat burrow. Cold season hibernation occurs in the muddy bottoms of waterways in communal hibernacula. Hibernacula usually have water depths of 55 to 95 cm (22 to 37 in) with a slow but steady flow or drift of water through densely vegetated wetlands with a deep, soft, mucky substrate (Carroll, pers. comm.). Muskrat burrows in Pennsylvania were used as winter hibernacula, nocturnal sleeping sites, refugia from danger, and estivation sites during the warm dry months (Ernst 1976). In Massachusetts, radio-tagged individuals hibernated in red maple-sphagnum swamps, then moved in late March to upland vernal pools, where they spent 3-4 months, then left the pools in August and spent 4-14 days in secluded terrestrial sites, then completed the move back to the swamps in August (Graham 1995). Eggs are laid in well-drained soil of marshy pasture, in grass or sedge tussock or mossy hummock, in open area (e.g., dirt path or road) at edge of thick vegetation, or similar site in sun. Sandy, sparsely vegetated strips and washouts along agricultural field edges are favorable for nesting (Carroll, pers. comm.).